In some reactive ink systems, fixers have been employed for the purpose of crashing colorants in ink. In inkjet printing, for example, fixer fluids are used to make reactive ink systems, whereby the fixer, upon contact with ink, causes the pigments and dyes in the ink formulation to precipitate out. The precipitated colorants deposit on the surface of the media, which results in the enhancement of image quality attributes, for example, optical density and chroma. Durability attributes like water-fastness and highlighter smear also benefit from such reactive ink chemistry. As a rule, both fixer and ink are formulated such that they reasonably well wet the media to which they are applied and quickly penetrate the media to avoid drytime related issues. This approach often results in non-uniform area fill, because the media itself is often inherently non-uniform. In areas where fiber density is low, fixer penetrates the media more quickly relative to denser areas. Consequently, ink colorants are precipitated out by the fixer at various depths from the media surface. These variations in depth are perceived as mottle (non-uniform area fill).